| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative electrode appropriate for lithium secondary battery having a high capacity by specifying a range of density of the mixture of graphite grains and binder, which forms a negative electrode, after pressurization and integration. SOLUTION: A negative electrode is formed by integrally forming the mixture of graphite grains and organic binder and a collector. Density of the mixture after integration is set at 1.5-1.9kg/cm<2> . Energy density per unit volume of a battery can be raised by raising density of the mixture, which forms the negative electrode. As a graphite grain, plural grains are collected or bonded so that an orientation surfaces thereof are not formed in parallel with each other. With this structure, since graphite grains are hard to be oriented on the collector, and since the graphite of a negative electrode becomes hard to store and release lithium, the quick charge and discharge characteristic and the cycle characteristic are improved. Graphite grains having aspect ratio at 5 or less is hard to be oriented on the collector, and gives the similar effect with the described graphite. |
